Micrometer to Mil/Thou Converter

Length Converter

31 units available

Decimals:

From

To

0.03937

1 µm = 0.03937 mil

Formula:

mil = µm × 0.0393700787

With your value: 1 µm = 0.03937008 mil

How big is that?

Everyday references on a logarithmic scale, all expressed in micrometer so you can sanity-check the result.

Your value1.00 µm

Grain of sand (5.0e+2× your value)500 µm

Credit card (long side) (8.6e+4× your value)8.56e+4 µm

A4 sheet (height) (3.0e+5× your value)2.97e+5 µm

Adult stride (7.5e+5× your value)7.50e+5 µm

Standard door height (2.0e+6× your value)2.00e+6 µm

Other Micrometer to Mil/Thou conversions

2 µm to mil 3 µm to mil 4 µm to mil 5 µm to mil 6 µm to mil 7 µm to mil 8 µm to mil

Micrometer to Mil/Thou Conversion Table

Micrometer (µm)	Mil/Thou (mil)
0.5	0.019685
1	0.03937
2	0.07874
5	0.19685
10	0.393701
15	0.590551
20	0.787402
25	0.984252
50	1.968504
100	3.937008
250	9.84252
500	19.685039
1000	39.370079

Mil/Thou to Micrometer Conversion Table

Mil/Thou (mil)	Micrometer (µm)
0.5	12.7
1	25.4
2	50.8
5	127
10	254
15	381
20	508
25	635
50	1,270
100	2,540
250	6,350
500	12,700
1000	25,400

Where these values come from

Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.

Micrometer (µm)

Length

Exact conversion

Traceable to the metre, defined by fixing the speed of light in vacuum at 299 792 458 m/s. Imperial lengths derive from the 1959 international yard (0.9144 m exactly).

Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)

Bureau International des Poids et Mesures · Reviewed 2026-07-01

Mil/Thou (mil)

Length

Exact conversion

Traceable to the metre, defined by fixing the speed of light in vacuum at 299 792 458 m/s. Imperial lengths derive from the 1959 international yard (0.9144 m exactly).

Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)

Bureau International des Poids et Mesures · Reviewed 2026-07-01

How to Convert Micrometer to Mil/Thou

To convert from Micrometer (µm) to Mil/Thou (mil), multiply the value by 0.0393700787.

Formula: mil = µm × 0.0393700787

Reverse: µm = mil × 25.4

Step-by-Step Example

Start with your value in Micrometer. For example: 5 µm
Multiply by the conversion factor: 5 x 0.0393700787
The result is: 0.19685 mil

About Micrometer

The micrometre (micron) equals one millionth of a metre. It is the working scale of cells, machining tolerances and airborne particulates.

Common uses: microscopy, machining tolerances, air quality (PM).

About Mil/Thou

A mil (or thou) is one thousandth of an inch, 25.4 micrometres. US manufacturing uses it for sheet, film and coating thickness.

Common uses: plastic film, PCB traces, coating thickness.

Frequently Asked Questions

How many Mil/Thou are in 1 Micrometer?

There are exactly 0.0393700787 Mil/Thou in 1 Micrometer. This means the conversion factor from Micrometer to Mil/Thou is 0.0393700787.

What is the formula to convert Micrometer to Mil/Thou?

The formula to convert Micrometer to Mil/Thou is: mil = µm × 0.0393700787. For example, to convert 10 Micrometer to Mil/Thou, you would multiply 10 by 0.0393700787.

What is a Micrometer?